Turmeric (Curcuma longa L.), belonging to the family of Zingiberaceae, is a perennial herb native to India where its rhizome is used as a yellow colorant curry spice and traditional medicine. The active principle in turmeric was identified as a group of polyphenolic compounds, namely curcumin (74-78%), demethoxycurcumin (15-18%) and bisdemethoxycurcumin (4-6%) commonly referred to as ‘curcumin’ (Aggarwal et al., chap. 23, Phytopharmaceuticals in Cancer Chemoprevention, 2004). It is one of the well-studied natural molecules and considered as one of the world's most important herbal extract.
Observational studies have already delineated the dietary intake of turmeric with a reduced incidence of chronic diseases such as Cancer and Alzheimer's in the subcontinent of India (C. M. Kaefer et al. J. Nutr. Biochem., 2008, 19, 347-361, K. Ramaswamy et al., Mol. Neurobiol., 2011, 44, 142-159). Turmeric is used as a dietary spice, coloring agent in foods and textiles, and a treatment for a wide variety of ailments. It is widely used in traditional Indian medicine to cure biliary disorders, anorexia, cough, diabetic wounds, hepatic disorders, rheumatism, and sinusitis. Besides flavouring food, turmeric is used to purify the blood and skin conditions. In Ayurvedic cooking, turmeric is used everywhere, this multifaceted wonder spice helps to detoxify the liver, balance cholesterol levels, fight allergies, stimulate digestion, boost immunity, enhance complexion and also used as a natural antioxidant. Ayurveda recognizes turmeric as a heating spice, contributing bitter, pungent and astringent tastes. Turmeric treats the whole Gastro-Intestinal system. In general turmeric is used for weak stomachs, poor digestion, dyspepsia, to normalize metabolism and enhance the ability of stomach to withstand digestive acids. Turmeric is a great carminative, able to calm an upset digestive system by getting rid of gas trouble and distension.
Modern scientific research has identified and characterized curcuminoids as the main bioactive principle in turmeric rhizomes, as responsible for majority of its pharmacological effects including antioxidant, anti-inflammatory, anticancer, anti-alzheimers, neuroprotective, gastroprotective, anti-bacterial and antithrombotic effects.
Most of the research with respect to curcumin is to find the pharmacological activities and mechanisms of action and bioavailability. Poor oral bioavailability has been demonstrated as the major problem which limits the transition of its therapeutic efficacy to the clinic. Hydrophobic and water insoluble curcumin undergo rapid biotransformations. Many patents and non-patent literatures are available on the methods to overcome the poor bioavailability of curcumin, but these documents are silent in discussing the methods to overcome hygienic process difficulties due to its color staining and dusting of the yellow pigment “curcumin”.
US 2011/0287085 A1: This invention provides a liposomal curcumin for treatment of cancer. The invention discloses compositions and methods for the treatment of cancer, including pancreatic cancer, breast cancer and melanoma, in a human patient. The methods and compositions of disclosed in this invention employ curcumin or a curcumin analogue encapsulated in a colloidal drug delivery system, preferably a liposomal drug delivery system. Suitable colloidal drug delivery systems also include nanoparticles, nanocapsules, microparticles or block copolymer micelles. However, this document is silent in discussing the process difficulties or bulk handling difficulties due to color explosion and dusting characteristics of curcumin.
US 2011/0274809 A1: This invention describes a method for masking curcumin flavour comprising mixing curcumin with a modified starch, however no information is available regarding on prevention color leaching of curcumin.
U.S. Pat. No. 4,307,117 A: This invention discloses a process to stabilize curcumin against color changes by maintaining the curcumin itself at low, stable pH values, while not upsetting the pH balance of a dry food mix which may be placed in contact therewith. Preferably, the pH of the curcumin is maintained at a value within the range of from about 3.5 to about 4.5, and comprises a spray-dried intimate mixture of curcumin, an organic acid, a buffer, a dispersant for the curcumin, and a film-forming encapsulant. A preferred use of the colorant is in dry mixes for instant puddings which are alkaline due to the salts employed to cause setting. However this record fails to teach ways to prevent the color leaching of curcumin by this method.
EP 2559347 A1: This invention describes a method for masking the pungent flavor of curcumin to obtain a preparation that can be taken without resistance. However no information is available regarding the prevention of color leaching of curcumin by this method.
JP 08-187066 A: This invention describes granular curcuma longa tea and its production. Sterilized curcuma longa is dried in the sun, dried in an atmosphere of hot air at 40-50° C. for 4-6 hours, further redried in an atmosphere of hot air at 65-75° C. for 8-12 hours and ground into a granular state to give the objective granular Curcuma longa tea. The Curcuma longa tea is preferably mixed with an herb which is dried and granulated or made into small pieces. However, no information is available regarding the prevention of color leaching of curcumin by this method.
EP 2249852 B1: This invention discloses stable water-soluble formulations of curcumin which make possible the manufacture of pharmaceutical and nutraceutical formulations of curcumin. However, no information is available regarding the prevention of color leaching of curcumin by this method.
US 2014/0031403 A: Describes forms of curcumin and the pharmaceutical compositions thereof. The forms of curcumin disclosed herein are curcumin polymorph Form III, curcumin-2-aminobenzimidazole co-crystal, and curcumin-L-lysine co-crystal. However this record does not teaches the prevention of color leaching or dusting of curcumin.
Amongst nutraceuticals and dietary supplements, curcumin supplements, especially tablets in enteric-coated forms and sustained release forms have been reported. Similarly, various encapsulation techniques to provide water dispersible, water soluble, stable and enhanced bioavailable formulations of curcumin are mentioned with relatively low amount of curcumin content ranging from 1 to 40% (w/w) or preferably from 10 to 20% (w/w). However no information on process difficulties or bulk handling difficulties due to color explosion and dusting or methods to produce curcumin powder, granules or beadlets containing not less than 90% curcuminoids without colour bleeding issues are described in the prior-arts.
Various methods for making curcumin from dried turmeric rhizome are known in the past. It generally involves preparation of oleoresins from turmeric rhizome by flaking, solvent extraction, and evaporation techniques. The oleoresin further undergoes crystallization and centrifugation to get wet cake. Dried cakes are then pulverized to prepare curcumin powder. The powder form is either used as such or perform granulation to modulate its density or flow properties suitable for capsules, tablets etc. However, no information to address the process difficulties or bulk handling difficulties of curcumin due to the color explosion and dusting characteristics have been discussed though it is a major issue of the curcumin processing industry.
Further, the color leaching or curcumin stains make the GMP production of curcumin products troublesome, expensive and non-hygienic. Once curcumin is produced, the entire plant need complete change over cleaning and it is done very often using organic solvents which makes the process and products expensive, time consuming and non-hygienic.
Hence there exists a long felt and unmet need to develop a green process to prepare curcumin powder and granule forms which can eliminate the problems discussed above, caused by color bleeding, dusting and staining characteristics of curcumin, without losing its biological effects.